AVIATION: Through the Sonic Barrier

On the flat land of Edwards Air Force Base
in California, a cluster of scientists and Air Force brass watched a
silvery, swept-wing jet fighter roar down the runway and into the air
for a test flight. It climbed high in the air, then leveled off and
shot across the air base with a roar like a thunderclap. This week Long
Island's Republic Aviation Corp. proudly announced the results of the
flight: its XF-91, powered by a General Electric J47 turbojet and a
Reaction Motors rocket engine, had become the first U.S. combat...